Intra-articular Monosodium Iodoacetate Research Articles

Comparison of the protective effect of the upper zone of the growth plate and unique cartilage matrix-associated protein with hyaluronic acid and corticosteroids on an experimental rat osteoarthritis model.

This study sought to compare the protective effect of the upper zone of the growth plate and unique cartilage matrix-associated protein (UCMA) with hyaluronic acid (HA) and corticosteroids (CS) in a rat model of osteoarthritis (OA). In the experimental animal study, 40 adult male rats were randomly assigned into five groups: control, monosodium iodoacetate (MIA) + vehicle (MIA+V), MIA+HA, MIA+CS, and MIA+UCMA. The OA model was induced by an intra-articular MIA injection to the right knee, and intra-articular injections into the right knee were performed on the treatment groups seven times every three days for 21 days. The knee joints were taken for histopathology and immunohistochemistry (IHC) analyses after the rats were sacrificed. All sections were stained with hematoxylin-eosin, safranin O and fast green FCF, and toluidine blue, and bone morphogenetic protein 2 (BMP-2) and nuclear factor-kappa B (NF-κB) expressions were analyzed with IHC. The Mankin scoring was utilized to determine the histopathological changes in the joint tissues. Mankin score was significantly higher in the MIA group compared to the control group. Histopathologically, in the UCMA-, HA-, and CS-treated groups, degenerations in the articular cartilage were milder than in the MIA+V group. Mankin score was found to be decreased significantly in the UCMA-, HA-, and CS-treated groups compared to the MIA group. Furthermore, IHC analyses revealed that NF-κB and BMP-2 expressions elevated in the MIA-induced OA model, while they were downregulated after UCMA, HA, and CS treatments. Our data revealed that UCMA could be used as a potential protective molecule in the prevention and treatment of OA. Furthermore, the protective effect of UCMA was similar to HA and CS, and its possible beneficial roles against OA may be linked to the reduced BMP-2 and NF-κB levels. Further experimental research would make significant contributions to a better understanding of the therapeutic effect of UCMA on degenerative cartilage tissues.

Eplerenone modulates the inflammatory response in monosodium iodoacetate-induced knee osteoarthritis in rats: Involvement of RANKL/OPG axis

AimsOsteoarthritis (OA) is a multifactorial degenerative disease marked by the progressive deterioration of articular cartilage with inflammation of the synovium. OA's main symptoms include pain and function loss. Monosodium Iodoacetate (MIA) experimental model is widely-used for OS induction since it produces symptoms comparable to those occurring in humans. Materials and methodsThirty-two rats were divided into four groups (n = 8). The 1st group received saline and included the normal-control rats. Groups 2–4 received intra-articular injections of MIA (3 mg/50 μL) in the rats' knee joints to induce OA. Group 2 included the MIA-control rats. Groups 3 and 4 received intra-articular MIA followed by a 14-day oral eplerenone (50 and 100 mg/kg); respectively. Key findingsIntra-articular injection of MIA in rats' knee joints caused significant inflammation and pain, elevation of Akt and ERK gene expression in knee joints along with significant alterations in the histological pictures of knee joints and OARSI scores. RANKL/OPG Axis was significantly disrupted. SignificanceEplerenone treatment produced a significant improvement in motor coordination and spontaneous locomotor activity in rats and modulated the key inflammatory mediators in OA (TNF-α, NF-κβ, and IL-6). Eplerenone also suppressed the qRT–PCR gene expression of Akt and ERK in knee joint tissues and improved the histological pictures and OARSI scores of knee joints of treated rats. Eplerenone caused a decline in RANKL concentration accompanied by a rise in OPG concentration thus modulating the RANKL/OPG Axis. Consequently, eplerenone is a candidate for OA therapy due to its potential anti-inflammatory effects.

Construction and pathological characterization of 3 animal models of temporomandibular joint degenerative joint disease in mice

Objective: To explore the pathological characteristics of three mice models of temporomandibular joint degenerative joint disease (TMJDJD), including osteoarthritis and osteoarthrosis, and to provide references for animal experimental study regarding the pathological mechanism of osteoarthritis and osteoarthrosis. Methods: A total of 54 8-week-old male C57BL/6 mice were selected to construct three TMJDJD animal models, including bilateral temporomandibular joint (TMJ) Freund's complete adjuvant (FCA) injection model, bilateral TMJ monosodium iodoacetate (MIA) injection model, and right TMJ discectomy model. FCA injection model (15 mice) was divided into saline injection group, FCA injection group-1 week, FCA injection group-2 week, FCA injection group-4 week and FCA injection group-6 week, 3 mice were used at each time point, with a total of 6 TMJs on both sides. MIA injection model (15 mice) was separated into saline injection group, MIA injection group-1 week, MIA injection group-2 week, MIA injection group-4 week and MIA injection group-6 week, 3 mice were used at each time point, with a total of 6 TMJs on both sides. TMJ discectomy model (24 mice) was split into control group, discectomy group-2 week group, discectomy group-4 week and discectomy group-6 week, six mice were used at each time point, with a total of six right TMJs. General pictures of the bilateral joints area of mice were collected 1 day after drug injection, and stereoscopic images of condylar tissues were collected 4 weeks after microsurgery for discectomy. Mouse TMJ tissue sections from each time point were stained with HE and toluidine blue, respectively, synovial tissues were scored for synovial inflammation, and the percentage of proteoglycan in condylar cartilage was quantitatively analyzed. Results: One day after intra-articular FCA or MIA injection, the width of bilateral TMJ were significantly increased in FCA injection groups [(24.60±0.46) mm] compared with the saline injection group [(21.63±0.52) mm] (t=4.25, P<0.013), the width of bilateral TMJ in MIA injection groups [(24.50±0.62) mm] were also significantly higher than that in saline injection group [(21.40±0.52) mm] (t=3.82, P=0.019). The synovitis scores in FCA injection groups 1, 2, 4, 6 weeks after FCA injection were significantly higher than that of the saline injection group (F=18.09, P<0.001), with the proteoglycan of condylar cartilage increased firstly and then decreased compared with the saline injection group (F=21.59, P<0.001). Condylar cartilage proteoglycan loss in different degrees were observed 1, 2, 4 and 6 weeks after MIA injection (F=13.59, P<0.001), and synovitis scores were increased at different degrees compared with saline injection group (F=14.79, P<0.001). The morphology of condylar cartilage in discectomy groups mice were severely damaged, synovial tissues showed dense connective tissue lesions at 2, 4 and 6 weeks postoperatively, condylar cartilage tissues showed a time-dependent loss of proteoglycan compared with the control group (F=40.62, P<0.001). Conclusions: Intra-articular FCA injection establishes a mouse model of TMJ osteoarthritis with severe synovial inflammation. Intra-articular MIA injection constructs a mouse model of typical TMJ osteoarthritis. Discectomy establishes a mouse TMJ osteoarthrosis model with severe condylar cartilage destruction.

Analgesic dorsal root ganglion field stimulation blocks both afferent and efferent spontaneous activity in sensory neurons of rats with monosodium iodoacetate-induced osteoarthritis

Chronic joint pain is common in patients with osteoarthritis (OA). Non-steroidal anti-inflammatory drugs and opioids are used to relieve OA pain, but they are often inadequately effective. Dorsal root ganglion field stimulation (GFS) is a clinically used neuromodulation approach, although it is not commonly employed for patients with OA pain. GFS showed analgesic effectiveness in our previous study using the monosodium iodoacetate (MIA) - induced OA rat pain model. This study was to evaluate the mechanism of GFS analgesia in this model. After osteoarthritis was induced by intra-articular injection of MIA, pain behavioral tests were performed. Effects of GFS on the spontaneous activity (SA) were tested with in vivo single-unit recordings from teased fiber saphenous nerve, sural nerve, and dorsal root. Two weeks after intra-articular MIA injection, rats developed pain-like behaviors. In vivo single unit recordings from bundles teased from the saphenous nerve and third lumbar (L3) dorsal root of MIA-OA rats showed a higher incidence of SA than those from saline-injected control rats. GFS at the L3 level blocked L3 dorsal root SA. MIA-OA reduced the punctate mechanical force threshold for inducing AP firing in bundles teased from the L4 dorsal root, which reversed to normal with GFS. After MIA-OA, there was increased retrograde SA (dorsal root reflex), which can be blocked by GFS. These results indicate that GFS produces analgesia in MIA-OA rats at least in part by producing blockade of afferent inputs, possibly also by blocking efferent activity from the dorsal horn.

Evaluation of Different Intraarticular Injection Therapies with Gait Analysis in a Rat Osteoarthritis Model.

Osteoarthritis (OA) is a degenerative disease that causes serious damage to joints, especially in elderly patients. The aim of study was to demonstrate the effectiveness of intraarticular therapies that are currently used or recently popularized in the treatment of OA. The baseline values were determined by walking the rats on the CatWalk system. Afterwards, a monosodium iodoacetate (MIA)-induced knee OA model was created with intraarticular MIA, and the rats were walked again on the CatWalk system and post-OA values were recorded. At this stage, the rats were divided into 4 groups, and intraarticular astaxanthin, intraarticular corticosteroid, intraarticular hyaluronic acid, and intraarticular astaxanthin + hyaluronic acid were applied to the groups, respectively. The rats were walked once more and posttreatment values were obtained. Nine different dynamic gait parameters were used in the comparison. Significant changes were measured in 6 of the 9 dynamic gait parameters after the MIA-induced knee OA model. While the best improvement was observed in run duration (P = 0.0022), stride length (P < 0.0001), and swing speed (P = 0.0355) in the astaxanthin group, the results closest to basal values in paw print length (P < 0.0001), paw print width (P = 0.0101), and paw print area (P = 0.0277) were seen in the astaxanthin + hyaluronic acid group. Astaxanthin gave better outcomes than corticosteroid and hyaluronic acid in both dynamic gait parameters and histological examinations. Intraarticular astaxanthin therapy can be a good alternative to corticosteroid and hyaluronic acid currently used in intraarticular therapy to treat OA.

Secretome of human adipose-derived mesenchymal stem cell relieves pain and neuroinflammation independently of the route of administration in experimental osteoarthritis

ObjectiveTreatment of pain associated with osteoarthritis (OA) is unsatisfactory and innovative approaches are needed. The secretome from human adipose-derived mesenchymal stem cells (hASC-Conditioned Medium, CM) has been successfully used to relieve painful symptoms in models of chronic pain. The aim of this study was to explore the efficacy of the hASC-CM to control pain and neuroinflammation in an animal model of OA. MethodsOA was induced in mice by intra-articular monosodium-iodoacetate (MIA) injection. Thermal hyperalgesia and mechanical allodynia were assessed. Once hypersensitivity was established (7 days after MIA), hASC-CM was injected by IA, IPL and IV route and its effect monitored over time. Neuroinflammation in nerve, dorsal root ganglia and spinal cord was evaluated measuring proinflammatory markers and mediators by RT-qPCR. Protein content analysis of secretome by Mass Spectrometry was performed. ResultsA single injection with hASC-CM induced a fast and long lasting antihyperalgesic and antiallodynic effect. The IV route of administration appeared to be the most efficacious although all the treatments were effective. The effect on pain correlated with the ability of hASC-CM to reduce the neuroinflammatory condition in both the peripheral and central nervous system. Furthermore, the secretome analysis revealed 101 factors associated with immune regulation. ConclusionWe suggest that hASC-CM is a valid treatment option for controlling OA-related hypersensitivity, exerting a rapid and long lasting pain relief. The mechanisms underpinning its effects are likely linked to the positive modulation of neuroinflammation in peripheral and central nervous system that sustains peripheral and central sensitization.

Inhibition of miR-203 Ameliorates Osteoarthritis Cartilage Degradation in the Postmenopausal Rat Model: Involvement of Estrogen Receptor α.

miR-203 is known to target estrogen receptor α (ERα) in various cancer cell lines, such as MCF-7. However, whether miR-203 regulates ERα and contributes to the onset and progression of osteoarthritis (OA) is poorly understood. A combined protocol of the bilateral ovariectomy and the intra-articular monosodium iodoacetate injection was applied to establish a postmenopausal OA model in rats. Real-time quantitative polymerase chain reaction was used to detect miR-203 and mRNAs and Western blotting was exploited to quantify the expression levels on the protein level. Enzyme-linked immunosorbent assays were deployed to detect the expression of matrix metalloproteinase-1 (MMP-1), MMP-3, prostaglandin E2 (PGE2), and collagen type II degradation (CTX-II) in serum samples. Dual-luciferase reporter assay was utilized to confirm the direct binding of miR-203 on ERα in postmenopausal OA rats. Expression of miR-203 was elevated; while ERα mRNA and protein were downregulated in postmenopausal OA rats, compared with sham rats. Dual-luciferase reporter assay confirmed miR-203 bound and negatively regulated ERα, resulting in promoted cellular inflammation and cartilage destruction in postmenopausal OA rats. Suppression of miR-203 using a specific inhibitor ameliorated cartilage degradation in postmenopausal OA rats. miR-203 is pivotal in the onset and progression of OA in the postmenopausal rat model, and holds promise for a therapeutic target of OA treatment.

Attenuation of IL-1ß on the use of glucosamine as an adjuvant in meloxicam treatment in rat models with osteoarthritis.

Background Osteoarthritis (OA) is the most prevalent joint disease and a common cause of joint pain, functional loss, and disability. The severity of this disease is always associated with increased levels of proinflammatory cytokines, which play an important role in cartilage damage, synovitis, and other damage to joint tissues. The discovery that many soluble mediators such as cytokines or prostaglandins can increase the production of matrix metalloproteinases by chondrocytes led to the first steps of an inflammatory state. Several studies show that cytokines, such as interleukin 1ß, have a major role in the development of inflammation that occurs in these joints. The use of glucosamine as an adjuvant to meloxicam therapy is expected to inhibit the development of inflammatory OA. Methods The OA model in rat was induced by single injection of intraarticular monosodium iodoacetate (MIA). The development of OA was observed for 21 days. Furthermore, the evaluation of glucosamine potency as an adjuvant of meloxicam therapy for reducing IL-1ß was done by combined treatment at a low dose of meloxicam 1 mg/kg BW with glucosamine at a dose of 125, 250, or 500 mg/kg BW orally for 28 days. Response to hyperalgesia and knee joint diameter was measured on days 0, 7, 14, 21, 28, 35, 42, and 49. IL-1ß levels were measured on day 21 and day 49 after MIA injection. Results MIA injection successfully induced OA as marked by a significant difference in the time of latency to heat stimulus (p < 0.01) and a significant increase in joint diameter (p < 0.01). On day 21, IL-1ß levels showed a significant decrease in MIA injection (p = 0.05). The administration of meloxicam and glucosamine did not induce significant decrease in knee joint diameter (p > 0.10), but was able to significantly increase the latency time to heat stimulus (p < 0.01). IL-1ß levels also showed a significant decrease after administering a combination of glucosamine and meloxicam (p < 0.01). Conclusions Taken together, the use of glucosamine as an adjuvant in meloxicam therapy may be caused by the synergistic mechanism of meloxicam for the attenuation of OA development through systemically reducing IL-1ß.

Anti-inflammatory Activity of Nanoemulgel formulated from Ageratum conyzoides (L.) L. and Oldenlandia corymbosa L. Extracts in Rats

The use of traditional medicine in the treatment of disease has increased globally due to its safety and efficacy. Ageratum conyzoides (L.) L. and Oldenlandia corymbosa L. have been used traditionally as a topical preparation for joint disease in Indonesia. Hence, the study was planned to scientifically study the existing empirical data. A nanoemulgel of combined Ageratum conyzoides (L.) L. (ACE) and Oldenlandia corymbosa L. Extract (OCE) as a new drug focused on plant-based natural products with a good physical characteristic that inhibits inflammatory process in managing osteoarthritis (OA) was formulated. Thirty animals were randomly designated to the 6 groups (n=5) as follows: (1) The normal control group (Normal), (2) negative control groups of Monosodium Iodoacetate (MIA), (3) combination ACE-OCE, (4) single ACE, (5) single OCE, (6) positive control group (Diclofenac). Rats received intraarticular MIA injection dose 3mg/0.05 mL on day zero excluding normal control group. All groups were administered topical preparations allotted to each dose group on day 29. Knee edema profile (every 7 days) and serum cytokine level (on day 57) was evaluated with Enzyme-Linked Immunoabsorbent Assay (ELISA). Till day 42, knee edema profile of all group treatment have been similar with normal control group (p>0.05). Serum cytokines level for some biomarkers, such as S100A8 Protein, Interleukin-1β, Inducible Nitric Oxide Synthase (iNOS), matrix metalloproteinase-13 (MMP-13), a disintegrin and metalloproteinase thrombospondin-like motifs-5 (ADAMTS-5), Collagen Type II and Aggrecan Core Protein were decreased. A significant difference compared with MIA group showed for all group treatment on measurement of S100A8 Protein, IL-1β, and iNOS as a biomarker of inflammatory process (#P<0.05). The developed nanoemulgel ACE-OCE either in single or in combination has good physical characteristic and promising effect of anti-inflammatory activity to enhance MIA induced cartilage damage as potential therapeutic agent for OA and encouraging to conduct further studies.

Protective effects of extracorporeal shockwave on rat chondrocytes and temporomandibular joint osteoarthritis; preclinical evaluation with in vivo99mTc-HDP SPECT and ex vivo micro-CT

Extracorporeal shockwave therapy (ESWT) has been shown to have chondroprotective effects on arthritic diseases. We investigated the effects of ESWT on temporomandibular joint osteoarthritis (TMJOA) using rat chondrocytes and TMJOA rat models. Cell viability and expression of pro-inflammatory cytokines, cartilage degradation, and apoptosis markers were measured in control, monosodium iodoacetate (MIA)-treated and ESWT plus MIA-treated chondrocytes invitro, and intra-articular MIA injection (TMJOA) and ESWT on TMJOA rats invivo. Invivo99mTc-hydroxymethylene diphosphonate (HDP) single-photon emission computerized tomography/computerized tomography (SPECT/CT) and ex-vivo micro-CT and histologic examinations were performed in rat models. ESWT plus MIA-treated chondrocytes showed increased cell viability significantly (P=0.007), while decreased genetic expression of pro-inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6); P<0.001 for each] and cartilage degradation markers [matrix metalloproteinase-3 (MMP3), matrix metalloproteinase-13 (MMP13), and bone morphogenetic protein 7 (BMP7); P<0.001 for each], and number of apoptotic cells (P<0.001) compared to MIA-treated chondrocytes. Changes in cytochrome c and cleaved caspase-3 levels relative to procaspase-3 were decreased over MIA-treated chondrocytes. ESWT on TMJOA rat models was associated with a significant decrease in pro-inflammatory and cartilage degradation markers, as demonstrated by real-time PCR and immunohistochemistry stains (P<0.001 for each). On 99mTc-HDP SPECT/CT, the ESWT group showed a significantly lower uptake ratio compared to the TMJOA group (P=0.008). Micro-CT analysis revealed that the ESWT group showed improved structure and bone quality compared to the TMJOA control group. ESWT was associated with a protective effect on cartilage and subchondral bone structures of TMJOA by reducing inflammation, cartilage degradation, and chondrocyte apoptosis.

Condylotomy to Reverse Temporomandibular Joint Osteoarthritis in Rabbits

Osteoarthritis (OA) of the temporomandibular joint (TMJ) is characterized by local tissue degeneration and pain. Treatments have been aimed at reducing symptoms, and only some can interfere with the progression of pathophysiologic changes caused by OA. Condylotomy is an alternative treatment for patients with OA refractory to conventional treatment. The aim of the present animal study was to investigate the influence of condylotomy on TMJ OA in New Zealand rabbits. The 36 rabbits were divided into 3 groups: the osteoarthritis group (OG; induced OA), treatment group (TG; induced OA plus condylotomy), and control group (CG; neither OA nor surgery). OA was induced using intra-articular monosodium iodoacetate injection for 40days. The rabbits in the TG underwent condylotomy and were killed 20, 40, and 60days after treatment. The rabbits in the CG and OG were killed at the same points. The articular joint condition was better in the TG 60days after surgery (P=.032). A direct comparison revealed regression of TMJ OA over time among the treated rabbits (P=.008). Surgical treatment promoted mandibular condylar remodeling in the TG, reversing the tissue degeneration caused by OA. Our findings suggest that condylotomy could be an option for the treatment of OA and prevent damage to TMJ structures. This could be of particular importance for patients without satisfactory responses to more conservative treatment.

Epicatechin and scopoletin rich Morinda citrifolia (Noni) leaf extract supplementation, mitigated Osteoarthritis via anti-inflammatory, anti-oxidative, and anti-protease pathways.

The scopoletin (coumarin) and epicatechin (flavonoid) rich Morinda citrifolia L. (MC) Noni leaves are non-toxic (unlike the fruits) and consumed as vegetables. The anti-osteoarthritis effects of the MC leaf extract against joint cartilage degradation and inflammation were investigated through cartilage explant cultures and pre-clinical animal study. Osteoarthritis were induced by intra-articular monosodium iodoacetate injection into the right knee. The extract, scopoletin and epicatechin, suppressed glycosaminoglycan and nitric oxide release from the cartilage explant in the presence of Interleukin-1β. After 28days, the extract treatment reduced the in vivo serum levels and joint tissues mRNA expressions for joint cartilage degradation, aggrecanase, and collagenase biomarkers. The extract increased the bone formation marker PINP levels, besides improving the articular cartilage structure and chondrocytes cellularity. The extract improved bone formation/repair, subchondral bone structure, strength and integrity, as well as cartilage synthesis by suppressing inflammation, nitric oxide production, joint catabolism by proteases, and oxidative stress. PRACTICAL APPLICATIONS: The scopoletin (coumarin) and epicatechin (flavonoid) rich Morinda citrifolia (Noni) leaves may be used as vegetables, functional food ingredient, or dietary supplements to suppress osteoarthritis progression against joint cartilage degradation and inflammation. The extract, scopoletin, or epicatechin, suppressed glycosaminoglycan, and nitric oxide release from the cartilage. The Morinda citrifolia leaf extract suppressed inflammation, nitric oxide production, tissues catabolism by proteases and oxidative stress to help reduce joint cartilage degradation, besides improving the articular cartilage structure, chondrocytes health, subchondral bone structure, bone formation/repair, and cartilage synthesis.

Ficus deltoidea Prevented Bone Loss in Preclinical Osteoporosis/Osteoarthritis Model by Suppressing Inflammation.

Osteoporosis (OP) and osteoarthritis (OA) are debilitating musculoskeletal diseases of the elderly. Ficus deltoidea (FD) or mistletoe fig, a medicinal plant, was pre-clinically evaluated against OP- and OA-related bone alterations, in postmenopausal OA rat model. Thirty twelfth-week-old female rats were divided into groups (n = 6). Four groups were bilateral ovariectomized (OVX) and OA-induced by intra-articular monosodium iodoacetate (MIA) injection into the right knee joints. The Sham control and OVX-OA non-treated groups were given deionized water. The three other OVX-OA groups were orally administered daily with FD extract (200, 400mg/kg) or diclofenac (5mg/kg) for 4weeks. The rats' bones and blood were evaluated for protein and mRNA expressions of osteoporosis and inflammatory indicators, and micro-CT computed tomography for bone microstructure. The non-treated OVX-OA rats developed severe OP bone loss and bone microstructural damage in the subchondral and metaphyseal regions, supported by reduced serum bone formation markers (osteocalcin, osteoprotegerin) and increased bone resorption markers (RANKL and CTX-I). The FD extract significantly (p < 0.05) mitigated these bone microstructural and biomarker changes by dose-dependently down-regulating pro-inflammatory NF-κβ, TNF-α, and IL-6 mRNA expressions. The FD extract demonstrated good anti-osteoporotic properties in this OP/OA preclinical model by stimulating bone formation and suppressing bone resorption via anti-inflammatory pathways. This is among the few reports relating the subchondral bone plate and trabecular thickening with the metaphyseal trabecular osteopenic bone loss under osteoporotic-osteoarthritis conditions, providing some insights on the debated inverse relationship between osteoporosis and osteoarthritis.

Monosodium iodoacetate induced osteoarthritis in the knee joint of growing rats: effects on bone as measured by micro-computed tomography

Purpose: Several experimental animal models in various species have been developed for human osteoarthritis (OA) and used to study the preclinical efficacy of disease and symptom modifying OA drug candidates. One of these models is induced chemically by an intra-articular injection of monosodium iodoacetate (MIA) into rat knee. Intra-articular MIA disrupts chondrocyte glycolysis through the inhibition of glyceraldehyde-3-phosphate dehydrogenase. This results in chondrocyte death and damage in the entire joint space, and leads to OA symptoms including joint pain similar to those observed in human patients. Previously, we have characterized the effects of intra-articular MIA on knee joint discomfort and pain, and on articular cartilage, synovium and bone in the knee joint of young adult rats. In this study, we characterized the effects of intra-articular MIA injection on bone in more detailed by high-resolution micro-computed tomography (micro-CT) both in the tibiofemoral and patellofemoral joints of growing rats. Methods: The study was conducted using growing male Sprague-Dawley rats. Unilateral OA was induced in their knee joints at the age of 6 weeks (150–183 g) by the intra-articular injection of MIA at the dose of 2 mg. The effects of MIA injection on body weight and bone in knee joint were followed during the study. Rats were terminated at 4 weeks after the MIA injection and their hind limbs were harvested for analyses. Knee joints were fixed and representative images were obtained by micro-CT (Skyscan 1276, Bruker microCT), from the entire knee joint including the distal end of femur, the proximal end of tibia and patella. In reconstructed micro-CT images, the entire epiphyses of tibia and femur and patella were separated, and tibial and femoral epiphyses were divided into medial and lateral compartments. Bone parameters in entire epiphyses, medial and lateral compartments and patella were analyzed by Bruker CTAn analysis software. This experimental protocol was approved by National Animal Experiment Board, Regional State Administrative Agency for Southern Finland, Hameenlinna, Finland. Results: Intra-articular MIA injection did not affect body weight gain in growing rats after 4 weeks post-injection. Representative micro-CT images demonstrated apparent tissue damage both in the tibiofemoral and patellofemoral joints of MIA-injected knee. The MIA injection decreased total bone volume in the entire epiphyses of tibia and femur similarly, namely by 44% in tibia and 47% in femur. However, total bone volume in the entire patella remained unchanged in MIA-injected knee. In weight-bearing region, the intra-articular MIA injection decreased bone volume by 44% in medial tibial plateau, 40% in lateral tibial plateau, 34% in medial femoral condyle, and by 29% in lateral femoral condyle. This suggested that bone in medial compartment was affected by MIA slightly more than bone in lateral compartment. These reductions in epiphyseal bone volume were associated with decreased number and thickness of individual trabeculae in epiphyseal marrow cavity. Conclusions: The present study characterized the effects of intra-articular MIA injection on bone in rat knee including both tibiofemoral and patellofemoral joints in the rat MIA model used widely in the preclinical efficacy studies of OA. In this study, the amount of MIA was higher and rats were younger than used in our previous studies. With these experimental settings, intra-articular MIA injection induced significant tissue damage and decreased bone volume in tibiofemoral joint. In patellofemoral joint, clear erosion was observed on articular surface without changes in total bone volume. High-resolution micro-CT demonstrated to be a useful tool to measure changes in bone and can be used when testing the preclinical efficacy of OA drug candidates in the rat MIA model. The follow-up of treatment effects by high-resolution in vivo micro-CT both on articular cartilage and bone would improve the analysis of preclinical efficacy in the rodent models of human OA.

Analgesic effects of morphine at rest and during movement on knee osteoarthritis induced by intra-articular monosodium iodoacetate in young rats

Analgesic effects of morphine at rest and during movement on knee osteoarthritis induced by intra-articular monosodium iodoacetate in young rats

The Effects of Intra-articular Monosodium Iodoacetate Injection on Joint Pain and both Tibiofemoral and Patellofemoral Joints in Rat Knee

Purpose: Several experimental animal models have been developed for human osteoarthritis (OA) and used to study the preclinical efficacy of disease and symptom modifying OA drug candidates in various species. One of these models is induced chemically by an intra-articular injection of monosodium iodoacetate (MIA) into rat knee. Intra-articular MIA disrupts chondrocyte glycolysis through the inhibition of glyceraldehyde-3-phosphate dehydrogenase, results in chondrocyte death and damage in the entire joint space, and leads to OA symptoms. Hitherto, most data of MIA-induced damage in rat knee has been obtained from tibiofemoral joint and not much information is available from patellofemoral junction. In order to improve this rat MIA model as the animal model of OA in preclinical efficacy studies, the effects of intra-articular MIA injection were characterized on the entire rat knee including both tibiofemoral and patellofemoral joints. Methods: The study was conducted using male Lewis rats. Unilateral OA was induced in their knee joints at the age of 3 months by the intra-articular injection of MIA at the dose of 1 mg. The effects of MIA injection on body weight and OA symptoms were followed during the study. Knee joint discomfort and pain were used as OA symptoms. The knee joint discomfort was determined as static weight bearing and measured as hind paw weight distribution using Incapacitance Tester. The knee joint pain was determined as static mechanical secondary allodynia and measured as paw withdrawal threshold using von Frey monofilaments. Rats were terminated at 4 weeks after the MIA injection and their hind limbs were harvested for analyses. Digital radiographs were obtained and both tibiofemoral and patellofemoral joints were analyzed in radiographs using Carimas software. Knee joints were fixed and representative images were obtained by micro-computed tomography. Then, knee joints were decalcified, embedded in paraffin, and sectioned in a coronal plane. The histological OA assessment of tibiofemoral joint was performed according to the recommendations of Osteoarthritis Research Society International (OARSI) histopathology initiative followed by the analysis of epiphyseal bone structure. Knee joints were also embedded in plastic without decalcification and sectioned in a sagittal plane. Both tibiofemoral and patellofemoral joints were analyzed by bone histomorphometry. For the determination of dynamic histomorphometry parameters, bone labelling was performed with oxytetracycline at 8 days and with calcein green at one day before sacrifice. This experimental protocol was approved by National Animal Experiment Board, Regional State Administrative Agency for Southern Finland, Hämeenlinna, Finland. Results: Intra-articular MIA injection into rat knee decreased paw withdrawal threshold, starting at 3 days after the injection and continuing up to the end of the study. This demonstrated the presence of mechanical hypersensitivity and neuropathic pain in MIA-injected hind limb. In tibiofemoral joint, the neuropathic pain was associated with mild to moderate degenerative changes demonstrated by increased total joint and tibial scores and increased cartilage degeneration width and volume. The cartilage degeneration included the loss of chondrocytes, proteoglycans and collagen matrix down to intermediate layer. These degenerative changes were observed together with a reduction in the amount of epiphyseal bone including decreased epiphyseal bone area fraction, decreased trabecular bone area fraction and decreased subchondral bone plate area. In MIA-injected patellofemoral joint, the neuropathic pain was associated with apparent damage including the degradation of articular surface both in femoral condyle and patella and a reduction in the density of subchondral bone in patella. Dynamic bone histomorphometry revealed impaired and ceased endochondral ossification in the articular cartilage of MIA-injected tibiofemoral and patellofemoral joints, respectively, in association with increased subchondral bone turnover. Conclusions: This study characterized the effects of intra-articular MIA injection on the entire rat knee including both tibiofemoral and patellofemoral joints together with OA symptoms in the rat MIA model used widely in the preclinical efficacy studies of OA. The injection of MIA induced a neuropathic pain in association with a significant damage both in tibiofemoral and patellofemoral joints. Therefore, treatment effects on the patellofemoral joint could be studied as well when testing the preclinical efficacy of OA drug candidates in the rat MIA model.

Osteoarthritis model induced by intra-articular monosodium iodoacetate in rats knee.

To evaluate the usefulness of a knee osteoarthritis model through functional, radiological and microscopic changes of the synovial membrane. Forty eight rats were divided randomly into two groups. The first received 0.9% saline in the joint and corresponded to the control group. The second was submitted to experimental osteoarthritis of the right knee induced by monosodium iodoacetate and corresponded to the osteoarthritis group. All animals were subjected to comparative tests of forced ambulation and joint movements, inability to articulate and tactile allodynia on day 1 post-experiment by forced ambulation (Roto-rod test), joint assessment of disability (weight bearing test) and assessment of tactile allodynia (Von Frey test). After inflammatory induction they were divided into four sub-groups corresponding to the scheduled death in 7, 14, 21 and 28 days when they were submitted to radiographic examination of the knee, arthrotomy and collection of the synovial membrane. The osteoarthritis group showed significant differences compared to control group on days 7 and 14 in Roto-rod, in weight bearing and Von Frey tests in all days, and in radiological evaluation. Microscopic examination of the synovial membrane showed abnormalities of inflammatory character at all stages. The osteoarthritis induced by intra-articular monosodium iodoacetate in rats knee is a good model to be used in related research, because it provides mensurable changes on joint movements, tactile allodynia, progressive radiological degeneration and microscopic inflammation of the synovial membrane, that represent markers for osteoarthritis evaluation.

Blocking the tropomyosin receptor kinase A (TrkA) receptor inhibits pain behaviour in two rat models of osteoarthritis

ObjectivesTropomyosin receptor kinase A (TrkA) mediates nociceptor sensitisation by nerve growth factor (NGF), but it is unknown whether selective TrkA inhibition will be an effective strategy for treating osteoarthritis (OA)...

Effect of alcoholic extract of Entada pursaetha DC on monosodium iodoacetate-induced osteoarthritis pain in rats.

Background & objectives:Osteoarthritis (OA) is a degenerative disease characterized by joint pain and progressive loss of articular cartilage. Entada pursaetha has been traditionally used in the treatment of inflammatory disease, liver ailment, etc. In this study we investigated suppressive effect of ethanolic extract of E. pursaetha (EPE) on monosodium iodoacetate (MIA)-induced osteoarthritis pain and disease progression by histopathological changes in joints in a rat model.Methods:OA was induced in right knee of rat by intra-articular injection of 3 mg of MIA and characterized by pathological progression of disease and pain of affected joint. Spontaneous movements, mechanical, thermal and cold sensitivity were monitored at days 0 (before drug and MIA injection), 7, 14 and 21 of MIA administration. EPE (30, 100 and 300 mg/kg), vehicle or etoricoxib (10 mg/kg; reference drug) were administered daily for 21 days by oral route.Results:EPE at various doses significantly reduced mechanical, heat, cold hyperalgesia and increased the horizontal and vertical movements in intra-articular MIA injected rats. EPE prevented the damage to cartilage structure and reduced the cellular abnormalities. Articular cartilage of rats treated with EPE at 300 mg/kg group was almost normal with well-developed smooth surface and chondrocytes were distributed individually or arranged in column.Interpretation & conclusions:The present findings showed that the EPE was not only able to mitigate pain and hyperalgesia but also inhibited MIA-induced cartilage degeneration in vivo. EPE may have the potential to become therapeutic modality in the treatment of osteoarthritis. However, further studies need to be done to confirm these findings in other models and clinical trials.

Augmented pain behavioural responses to intra-articular injection of nerve growth factor in two animal models of osteoarthritis

ObjectivesNerve growth factor (NGF) is a promising analgesic target, particularly in osteoarthritis (OA) where existing therapies are inadequate. We hypothesised that pain responses to NGF are increased in OA joints....